Electrohydrodynamic fluid pump



Aug. 23, 1966 "r. T. BROWN ELECTROHYDRODYNAMIC FLUID PUMP Filed Dec. 51, 1964 I'll,

I II/'/' I/' F IGS INVENTOR. THOMAS TOWNSEND BROWN W ATTORNEY United States Patent 3,267,860 ELECTROHYDRODYNAMIC FLUID PUMP Thomas Townsend Brown, Matvern, Pa., assignor, by mesne assignments, to Martin M. Decker, Montgomery County, Pa.

Filed Dec. 31, 1964, Ser. No. 422,839 Claims. (Cl. 103-1) This invention relates to fluid pumps and more particularly to fluid pumps for pumping dielectric fluids. This is a continuation-in-part of my application Serial No. 793,893, filed February 17, 1959.

In my above-mentioned application, I disclosed a pump for dielectric fluids which does not require moving parts. I have discovered an improved device by which electrical energy may be converted directly into kinetic energy in the form of moving dielectric fluids. Accordingly, this device may be employed to pump dielectric fluids such as air, oil, gases or dielectric solids suspended in a gas through the system. These propulsive forces act upon the dielectric fluid due to the unique geometry of the electric fields. These electric fields may be shaped in a manner to produce a propulsive force on the fluid dielectric by the geometry of the electrodes and by the use of a rod electrode extending from the smaller end of a frustoconical electrode toward the larger end of the next adjacent frusto-conical electrode. Preferably, a rod electrode extends from each conical electrode and is positioned axially of the conical electrodes. The electrodes are immersed in the dielectric fluid and different electrical potentials are applied to the electrodes from a source of high voltage. Reversal of the polarity of the voltage applied to these electrodes makes little difference upon the magnitude or direction of the force developed in the surrounding fluid medium. One or the other of the electrodes may be grounded it convenient. It has been found that generally better results are obtained if the rod electrodes are positioned axially of the conical electrodes and extend at least to the plane containing the larger aperture of the next adjacent electrode. When the electrodes are differentially charged, the dielectric fluid medium near the axis of the annular electrodes is set in motion and flows through the conical electrodes and around the rod electrodes or extensions of the conical electrodes.

In accordance with aspects of this invention, a number of annular frusto-conical electrodes, each but the last having a rod-like axial extension, are positioned with their axes coincident and these electrodes are connected to a source of potential which applies increasingly higher potentials from one end of the series of electrodes. With this arrangement, a propulsive force is produced on the immersing dielectric fluid in a direction axially of the frusto-conical electrodes.

In accordance with other aspects of this invention, a number of annular frusto-conical electrodes, each but the last having a rod-like axial extension, are mounted with their axes coincident and these electrodes are charged in alternate groups to different potentials. When so charged, a propulsive force is produced on the dielectric fluid surrounding the electrodes to produce a pumping action or flow of fluid through the frusto-c-onical electrodes and around the rod-like extensions in a direction along the axes of the electrodes.

In accordance with yet other aspects of this invention, the extension is constructed with an insulating rod formed of material such as plastic or ceramic, coated with a resistive material such as carbon, and the coating is electrically connected to the electrode supporting the projection. Preferably, the resistance between the electrical connection to the electrode and the opposite end of the coating is of the order of ten to twenty megohms. If an Patented August 23, 1966 are occurs between the extension and the next electrode, the resistive coating will act as a voltage limiter and arc suppressor.

Accordingly, it is a feature of this invention to employ as an electrohydrodynamic pump a series of annular frusto-conical electrodes, each but the last having a rod electrode extending from its smaller aperture toward the next electrode, and positioned with their axes coincident in sealed relationship to the inner surface of a dielectric tube in a dielectric fluid and charged in a serial fashion by a high voltage source to produce flow of the dielectric through the electrodes and around the rod electrode.

It is another feature of this invention to employ as a dielectric material pump, a plurality of annular frustoconical electrodes positioned in sealed relationship to the interior of a dielectric tube with their axes coincident and each but the last having an axial extension thereon, and to connect alternate ones of these electrodes to different terminals of a high voltage source such that the dielectric material flows along the axis of the tube in response to the shaped electric field produced by the electrodes.

It is still another feature of this invention to employ, as a dielectric material pump, a plurality of frust-o-conical electrodes positioned in fluid sealing relationship to the interior of a dielectric tube with their axes coincident, with each but the last having a resistive projection thereon and extending along the axes to enhance the pump efficiency and act as an arc suppressor when a high voltage direct current potential difference is applied between the electrodes.

These and various other objects and features of this invention will be more clearly understood from a reading of the detailed description of this invention in conjunction with the drawing in which:

FIGURE 1 is a combined schematic and perspective view, partly in section, of one illustrative embodiment of this invention;

FIGURE 2 is a combined schematic and perspective view, partly in section, of another illustrative embodiment of this invention;

FIGURE 3 is an end view of one electrode of the type shown in FIGURES l and 2, as viewed from its left-hand end in FIGURES 1 or 2;

FIGURE 4 is a side elevational view of the electrode of FIGURE 3;

FIGURE 5 is an end view of an alternative embodiment of electrode corresponding to the view of FIGURE 3; and

FIGURE 6 is a side elevational view of the electrode of FIGURE 5.

Referring now to FIGURE 1, there is depicted a combination perspective and schematic View, partly in section, of one illustrative embodiment of this invention. A pump device 10 for moving dielectric material includes a series of conical conducting surfaces, or electrodes, 12, 14, 16 and 18, each having its outer surface engaging the inner surface of a tube 20 in fluid sealing relationship. A serially ascending direct current potential is applied to these electrodes from a high voltage source 22'connected to a voltage divider including resistors 24, 26 and 28 through conductors 25, 27, 29 and 31. The dotted line 30 indicates that an infinite number of stages or series of electrodes may be employed and that they will each be connected to a point on the voltage divider coresponding to their position in the tube 20. The source 22 supplies a potential of the order of at least 8 to 50 kv. to the series of electrodes 12, 14, 16 and 18 and the rate of movement of a dielectric axially along the tube varies with the applied potential, as long as the breakdown or arcing potential is not exceeded.

Advantageously, each electrode of the series except the last has a rod-like conducting extension thereon extending toward the electrode having the adjacent larger opening (i.e., to the right as viewed in FIGURE 1) to produce an annular electric field which improves the electro-kinetic force on the dielectric material as compared to electrodes without extensions. For example, electrode 12 has a rod-like metallic extension 32 mounted on a tripod including members 33, 34 and 35, which position the rod 32 axially relative to the electrode 12 and to the tube 20. Preferably, the rod 32 extends to a position within the electrode 14 and the preferred embodi ment extends substantially the entire length of the next conical surface. The electrodes 14 and 16 and any electrodes added within the series have axial extensions thereon, such as extension 36 and 38, supported by suitable tripods on electrodes 14 and 16, respectively.

FIGURE 2 shows an alternative connection of the electrodes 12, 14,16 and 18 in which electrodes 12 and 16are connected to one terminal of source 22 and electrodes 14 and 18 are connected to the other terminal. If additional electrodes are added, first alternate ones are connected to the left-hand terminal of source 22 and second alternates ones are connected to the right-hand terminal. Here, again, the rod-like conducting extensions aid in the production of electro-kinetic force and increase the flow of material through the tube 20, as compared to my earlier device disclosed in my above-mentioned application. FIGURES 3 and 4 are end and side views, respectively, of a single electrode 12 showing the tripod mounting and axial position of the extension 32. Each of the electrode extensions is formed of conducting material such as copper and is similarly oriented.

FIGURES 5 and 6 are views corresponding to the views of FIGURES 3 and 4, respectively, and showing an alternative embodiment and arrangement of electrode extension 50 in which the extension is formed of a single member having a curved portion 51 extending from the conical portion and a straight portion 52 of sufiicient length to project to a position within the next electrode of the device. In this particular embodiment, the straight portion 52 is formed of an insulating rod 54 of plastic or ceramic material and coated with a suitable resistive coating 56, such as carbon or manganin. The coating is connected through curved portion 51 to the electrode 12. When a high direct current potential is applied to the electrodes 12, 14, 16 and 18 and the electrodes 12, 14 and 16 have resistive type extensions, an annular field will be produced around the resistive extensions which aids the pumping action. If an arc occurs, it will occur between the end of the extension closest the next electrode and the current to this are must flow through the resistive coating 56. Because the resistance of the coating is high (preferably at least ten megohms) the voltage drop across the extension will reduce the voltage between the extension and the next electrode below the arc-sustaining potential. Thus, this embodiment of extension acts as an arc suppressor and permits the ap- 4 plication of higher potentials between electrodes than the embodiment of FIGURES 1-4.

While I have shown and described various embodiments of my invention, it is understood that the concepts and features thereof may be incorporated in other embodiments without departing from the spirit and scope of this invention.

What is claimed is:

1. A pump for dielectric fluids comprising an insulated tube through which said fluids may pass, an equispaced series of baffles in the form of electrically conducting annular truncated cones, each having an outer surface engaging said tube, said cones being axially aligned within said tube and all but one of said electrodes including an axially extending rod and means for maintaining different electrical potentials upon the successive cones of said series.

2. An electro-kinetic device for moving dielectric material comprising a series of annular conical electrodes encased in a dielectric conduit and each having a rod extending axially therefrom toward the larger opening in the next electrode and means for applying electrical potentials to the electrodes.

3. An electro-kinetic device for moving dielectric material through a dielectric tube comprising a spaced series of annular conical electrodes, each having an outer surface engaging the inner surface of said dielectric tube, certain of said electrodes having a conducting extension electrically connected thereto and axially aligned with the electrode to which the extension is connected and means for applying a direct current potential between adjacent ones of said electrodes.

4. An electro-kinetic device for moving dielectric material comprising a spaced series of annular conical electrodes encased in a dielectric tube, certain of said electrodes having a resistive extension electrically connected thereto and axially aligned with the electrode to which the extension is connected and means for applying a direct current potential between adjacent ones of said electrodes.

5. A device according to claim 4 wherein said resistive extensions include an insulating rod with a resistive coating thereon, said coating being electrically connected to the .respective electrode on which the extension is mounted.

References Cited by the Examiner UNITED STATES PATENTS 1,928,963 10/1933 Chaifee 103-1 2,295,152 9/ 1942 Bennett 230-69 2,303,321 172/ 1942 Bennett 230-69 2,333,144 11/1943 Bennett 230-69 2,578,908 12/1951 Turner 103-1 3,054,553 9/1962 White 103-1 3,071,705 1/1963 Coleman et a1. 103-1 FOREIGN PATENTS 1,246,669 10/ 1960 France.

LAURENCE V. EFNER, Primary Examiner. 

1. A PUMP FOR DIELECTRIC FLUIDS COMPRISING AN INSULATED TUBE THROUGH WHICH SAID FLUIDS MAY PASS, AN EQUISPACED SERIES OF BAFFLES IN THE FORM OF ELECTRICALLY CONDUCTING ANNULAR TRUNCATED CONES, EACH HAVING AN OUTER SURFACE ENGAGING SAID TUBE, SAID CONES BEING AXIALLY ALIGNED WITHIN SAID TUBE AND ALL BUT ONE OF SAID ELECTRODES 